As illustrated in FIG. 2, the tag pin consists of a head H, a transverse bar B and a filament F for interconnecting the head to the bar. In producing the tag pin, an interconnecting portion C is disposed in the direction of extension of the filament F and is connected to an interconnecting rod R to form a fastener or tag pin assembly T (hereinafter referred to as the "tag pin assembly") which has a comb-like shape as a whole.
The tag pin assembly T is molded from a linear high polymer such as nylon, polypropylene or the like.
In ordinary production methods of the tag pin assembly T, a mold is heated to a high temperature and a hot-melt resin is charged into the mold. The tag pin assembly T thus obtained is crystallized as a whole. When the filament F interconnecting the head H to the transverse bar B is stretched, molecular orientation takes place so that the filament becomes tough and thin and stiffness increases at the interconnecting portion between the filament F and the transverse bar B. This facilitates the punching work of the tag pin to a commodity by use of the tag attaching device in order to put the tag to the commodity. In addition, since the filament is thin, it does not damage fiber products.
However, in the tag pin produced by these methods, the filament has already been stretched so that a large number of pairs of socks or gloves, for example, can not be bundled firmly.
Another problem is that if the length of the filament is predetermined, tag pins having various lengths must be prepared to meet with intended applications. Since the mold and product management become thus complicated, the cost of production of the tag pins becomes unavoidably higher.
To eliminate the problem with the conventional tag pin having the stretched filament, the inventors of the present invention developed a tag tip whose filament could be stretched when the tag was punched by the tag attaching device. This tag pin could be obtained by rendering at least the filament portion non-crystalline. As the filament of this novel tag pin could be stretched when the tag pin was punched by the tag attaching device, the filament length could freely be adjusted. Commodities bundled by this tag pin exhibited unitary and excellent packaging form. An advantage for product management could also be obtained because tag pins suited for plural applications could be produced using one kind of mold.
When the tag pin having the stretchable filament was loaded to the ordinary tag attaching device and punched to a commodity, however, a critical problem was found out. For, since the non-crystalline filament can be stretched at room temperature, it does not need any heat-stretcher, in particular, but the stretching starting state is extremely delicate. At the start of stretching, necking (contracted portion) occurs at a part of the filament to rapidly reduce its cross-section and then this contracted portion propagates in the direction of length of filament. In conjunction with the stretching behaviour, filament is cut if tension is quickly applied until necking occurs but once necking does occur, the filament does not break up to a considerably high stretching speed.
Meanwhile, punching of the tag pin by use of the conventional tag attaching device is carried out in the same routine as that of the tag pin having the stretched filament. As shown in FIG. 1, the tag attaching device has a pistol-like shape and as its grip 2 is gripped, the transverse bar of the tag pin is pushed into a needle equipped with a groove. However, since the lever gripping speed is considerably high, the transverse bar of the tag pin is pushed into the needle equipped with a groove at a speed which is by far higher than the stretching speed that is optimal for the occurrence of necking. Hence, the filament is likely to break.
To eliminate this problem, the inventors of the present invention have examined the stretching speed and have found that breakage of the filament can be prevented almost perfectly if the lever of the tag attaching device is gently pulled at the initial stage so as to push the transverse bar of the tag pin at a slow speed and thereafter the lever is pulled at an ordinary speed.